Transcript Abiotic

Introduction to
Ecology
Science 10
Ecology
 Scientific study of the interactions of
organisms and their environment
 Involves observations and experiments to
test hypothetical explanations of
ecological phenomena.
 Explores the interactions of organisms
and their environment as well as how the
environment affects the organism.
Ecosystem
 Is a community of organisms and the
physical environment in which it lives.
Example:
When an ecologist studies the organisms
living in a forest and includes a study of
the physical factors that affect the
organisms in the forest, then the
ecologist is studying an ecosystem.
Abiotic Factors
 Are the non-living factors which affect life in
an ecosystem.
Examples to be studied:
1. Space
2. Temperature
3. Oxygen
4. Sunlight
5. Water
6. Inorganic & Organic Soil Nutrients
1. Space
 All organisms require
enough space or
territory to insure
(guarantee) adequate
resources such as
food, water, shelter,
and mates.
2. Temperature
 Environmental temperature
affects biological processes and
the ability of most organisms to
regulate their temperature.
 Few organisms have active
metabolisms at temperatures
below 0oC or above 45oC
because enzymes function best
within a short range of
temperature and become
denatured if the temperature is
too high.
Enzyme
 Naturally occurring catalyst found in the
body that helps chemical reactions to
occur at body temperature (cellular level).
 A catalyst speeds up a chemical reaction
and is not changed by the reaction –
therefore it can be used over and over
again.
Example
 Enzymes are very important in digestion.
They help act as catalysts to break down
the big molecules (which cannot pass
through the stomach wall into the blood)
into smaller ones (which can diffuse into
the blood).
 Starch, proteins and fats are big
molecules. Sugars, amino acids and fatty
acids/ glycerol are much smaller.
Examples: Amylase, Protease, Lipase
Temperature & Type of
Vertebrates
2 main types of vertebrates:
1. Ectotherms
2. Endotherms
Ectotherms


Are cold-blooded organisms.
They can maintain their body
temperature only within a
few degrees of ambient
temperature (temperature of
the environment or
surroundings).
Examples:
Reptiles or amphibians
Endotherms
 Warm-blooded organisms.
 Are able to control their
body temperature.
 No matter what the
temperature is outside, their
internal body temperature
remains the same.
Examples:
Mammals (dolphin,
elephant, humans)
3. Oxygen
 Most living organisms require oxygen for
cellular respiration, which is a process
that releases energy from food.
 Organisms obtain (or get) oxygen
differently.
There are 2 main types
1. Terrestrial organisms
2. Aquatic organisms
Terrestrial Organisms
 “terrestris” Latin for
“earthly”
 Take oxygen from the
atmosphere usually
through their lungs.
Examples:
Humans, iguanas,
whales, frogs
Aquatic Organisms
 “aqua” Latin for “water”
 These organisms use
gills to extract the
oxygen dissolved in
water.
Examples:
Fish and tadpoles
4. Sunlight
 Is the ultimate source of
energy for all organisms.
 It is needed for organisms
that use sunlight for
photosynthesis.
Photosynthesis:
Plants use the energy in
sunlight to convert carbon
dioxide from the atmosphere
into simple sugars.
Sunlight
 Also affects the development and
behaviour of many organisms
 This is called photoperiod (Greek “photos”
means light and “periodos” means “time”).
Examples:
Plants that flower, trees in autumn, change in
the colour of furs and feathers, migration,
hibernation, mating patterns, and for humans,
seasonal depressive disorder (SDD)
Water
 Water (humidity) is
necessary for all life.
 Organisms need to be
able to find water,
maintain water balance,
and to conserve water
 All of these things help
determine the habitat
range for each species.
Why drink water?
 Your body needs water to
regulate body temperature
and to provide the means
for nutrients to travel to all
your organs (liquid
medium).
 Water also transports
oxygen to your cells,
removes waste, and
protects your joints and
organs.
6. Inorganic & Organic
Soil Nutrients
Inorganic soil nutrients:
include minerals such as phosphates (PO43-),
nitrates (NO3-), potassium (K+),
magnesium (Mg2+) and a host of other
minerals derived from rocks.
Organic nutrients:
include organic compounds in humus which
promote the growth of bacteria, fungi, and a
host of other organisms beneficial to the soil.
Humus
 Dark, rich soil that is
created from the
decomposition of
“organic” material.
 Remains of living
things such as
deceased plant or
animal life.
In terms of soil, remember
that:
1. physical structure
2. water holding potential
3. pH
4. nutrient level of soil
…limits the distribution of plants and in turn the animals
that inhabit a terrestrial region.
 For aquatic regions we consider the composition of
the substrate (soil under the stream) and how it
affects the chemistry of the water above and the plant
and animal life living there.